VSCode keybinding to switch between terminals

keybindings.json

// Place your key bindings in this file to override the defaults
[
  {
    "key"    : "shift+right", //"ctrl+down" is not working
    "command": "workbench.action.terminal.focusNext",
    "when"   : "terminalFocus",
  },
  {
    "key"    : "shift+left", //"ctrl+up" is not working
    "command": "workbench.action.terminal.focusPrevious",
    "when"   : "terminalFocus",
  },
]